The structure of the hydrochloride salt of 1-deoxynojirimycin [(1R,3R,
4R,5S)-3,4,5-trihydroxy-2-(hydroxymethyl) piperidinium chloride, C6H14
NO4+.Cl-] is reported. The cation has an almost undistorted C-4(1) con
formation. The crystal structure is built up from alternating layers o
f cations and anions interconnected by a three-dimensional network of
hydrogen bonds. Each chloride ion is coordinated through four hydrogen
bonds and there are also two intercationic hydrogen bonds.